1. Field of the Invention
The present invention relates to an injection molding system, and particularly, to an injection molding system including an injection molding apparatus, a conveyor device configured to convey molded articles produced by the injection molding apparatus, and an inspection device configured to inspect the molded articles conveyed by the conveyor device.
2. Description of the Related Art
To detect a defective article generated in molded articles produced by an injection molding apparatus, each molded article must be determined as non-defective or as defective. Whether a molded article is non-defective or defective can be determined by directly inspecting the molded article by visual observation with human eyes or by using machines. Alternatively, instead of such direct inspection, the quality of a molded article can be indirectly determined by examining physical quantities such as an injection pressure, an injection speed, a position, and a temperature when producing a molded article in the injection molding apparatus.
More specifically, a molded article can be directly inspected to determine the quality by measuring the physical quantity such as size or weight of the molded article to find whether or not the measured value is within an allowable range, and by visually inspecting the appearance of the molded article by a vision sensor or by human eyes.
JP 03-207616 A discloses a molded article inspection apparatus in which an injection molding apparatus automatically determines the quality of a molded article. In the molded article inspection apparatus, the weight of a molded article extracted at every shot of the injection molding apparatus is measured automatically. The quality of the molded article is determined by fetching the measured value of the weight together with a plurality of monitored items such as a primary pressure, a secondary pressure, and a primary injection time.
JP 2002-46146 A discloses an injection molding apparatus for molding a connector housing as a resin product and a conveyor belt for receiving and conveying the resin products dropped from the injection molding apparatus. JP 2002-46146 A also discloses a weight inspection device for inspecting the weight of a molded connector housing after conveyed by the conveyor belt.
According to the technique disclosed in JP 03-207616 A, a molded article is subjected to direct inspection immediately after molding by the injection molding apparatus. Thus, the relationship between the molding data of the injection molding apparatus and the quality of an actual molded article measured by the inspection is made clear by collecting the inspection data obtained by the inspection and the molding data for producing a molded article in association with each other as a set. By feeding back the relationship between the molding data and the inspection data, improvement of the quality of the molded articles is facilitated. However, a cycle time may increase by the time required for inspection as the inspection is performed immediately after the injection molding apparatus produces a molded article. In addition, even though the inspection is performed immediately after molding at which a molded article is not sufficiently solidified, the state of the molded article may have changed at the time when the molded article is completely solidified.
According to the technique disclosed in JP 2002-46146 A, a molded article produced by the injection molding apparatus is conveyed by the conveyor belt to an inspection place of the inspection device to be subjected to inspection. This may cause difficulty in storing the results of inspection by the inspection device and molding data of the injection molding apparatus when producing a molded article in association with each other, since inspection of a molded article is delayed from the timing at which a molded article is produced for a time period until the molded article is conveyed by the conveyor belt to the inspection place, and is performed separately at a different place.